I’ve always been particularly drawn to excellent student performances, like this one from The Treble Makers (later called Kaleidoscope):

When expectations for a student concert necessarily start lower than for a professional performer, it’s all the more impressive to see a group so entirely excel. I also like Mr. Sandman by the same quartet. I sang in my high school’s choir, and I’m absolutely certain I never attained anywhere near this level of musicality.